MACS/WIHS Combined Cohort Study (MWCCS) Administrative Supplements for the proposed project, ?COVID-19 and the MWCCS: Psychosocial and Structural Impact on Physical and Mental Health, and HIV Prevention Behaviors? Abstract. Older adults and people with comorbid conditions are at increased risk for severe illness from COVID-19. Given the older age of our research participants and the higher prevalence of comorbid conditions among people living with HIV (PLWH), PLWH are at increased risk for severe disease outcomes resulting from COVID-19. However, while many of our MWCCS research participants may not have tested positive, mental health challenges, social isolation and psychosocial stressors may have disproportionally impacted access to health care, health outcomes and prevention behaviors. Qualitative interviews will allow for in- depth accounts and perceptions provided by participants, sharing their experiences of dealing with the COVID-19 pandemic and associated risks and restrictions. The proposed research will provide critical insights into the multilevel impact of the COVID-19 pandemic and its associated public health orders on the health and well-being of PLWH and those at-risk for HIV across the U.S. Results from this study will elucidate unforeseen consequences of public health efforts on vulnerable populations that are at higher risk for comorbidities, stigma and discrimination and socioeconomic hardship. Data from this study will help to inform future studies and public health efforts to prepare for interruptions in health care and study participation due to natural disasters or public health emergences.